search for: hasloopzerocosttopology

...HW-loop conflict with unrolling etc. So optimizer has no idea how to use this interface. If you just call this interface to disable unrolling, that would be overkill on some arch which has HW support, as on such arch HW-loop and unrolling are orthogonal. - hasLoopZeroCostTopology(Loop *L, unsigend TripCount) Why trip-count? It can be derived from the loop itself. Which optimizer will call this interface? I would suggest following interface: /// get unrolling factor of given *INNERMOST* loop from HW's perspective. /// Note: this interface is f...

...rator, which doesn't make things any simpler. I think we are going off-topic. I'm not proposing new llvm instructions to introduce hw loop semantics. What I'd like to do is to find a good interface between the loop unroller and targets to prevent loop unrolling. hasZeroCostLoop() and hasLoopZeroCostTopology(Loop *L, unsigend TripCount) has been proposed so far. Ivan > > Thanks > Shuxin > > On 11/22/2012 02:56 PM, Gang Yu wrote: >> Hi shuxin, >> >> Promote while-loop to do-loop is the job of loop induction >> recognized, not this transformation. The scalar tra...

Hi, Gang: I don't want to discuss Open64 internal in LLVM mailing list. Let us only focus on the design per se. As your this mail and your previous mail combined give me a impression that : The only reason you introduce the specific operator for HW loop in Scalar Opt simply because you have hard time in figure out the trip count in CodeGen. This might be true for Open64's